Rock-drill.



No. MHUJH. Patented lan. 2, i900, G. D. WHETCOIMB El. W. K. MILLHULLND.

BUCK DRILL.

(Application tiled May 20, 1899.)

4 Sheets-Sheet lA l ik Tm: mams PETER: ca. vnomurncv, wruwlrcnA u. ci

No. www.

Patented lan. 2, |909. G. D. WHITCUMB W. K. MILLHULLAND.

' ROCK DRILL (Application filed May 20, 1899.)

4 Sheets-Sheet 2.

(No Mode.)

No. MJUAH. Patented Jan. 2, |900. G. D. WHITCUIMB W. K. MILLHLLND.

ROCK DRILL (Application filed May 20, 1899.) (N0 WIOGL) 4 Sheets-Sheet 3.

@e Il mii Q No. @fimm Patented lan. 2, |900.

G. D. WHITEMB W. K. WIILLHULLAND.

ROCK DRILL.

(Application filed May 20, 1899.) (No Model.) 4 Sheets-Sheet 4` *rare l laica enonen n. tvuirootm, or GLENDORA, OALIFORNM., AND Wmmruu n. MILLHOLLAND, or OuioAeO, ILLrNois.

uooumoaut..

SPEGIFOATION forming part of Letters Patent No. 640,341, dated January 2, 1900.

Application filed May 20, 1899.

-COMB, a resident of Glendora, county of Los Angeles, and State of California, and EVIL- Lrnn K. MILLHOLLAND@ resident of Chicago,

lCook county, and State of Illinois, citizens of the United States, have invented certain new and useful improvements in Rook-Drills, of which the following is a specification, and Which are illustrated in the accompanying drawings, forming a part hereof.

The invention relates to power-actuated impact-drills, more particularly to what are known as pneumatic drills, and has special reference to the mechanism for causing the rotation of the drill; and it consists in the various parts and arrangements of parts, as hereinafter fully described and as illustrated in the accompanying' drawings, in Which- Figure l is a longitudinal vertical central section of the machine. Fig. 2 is a plan section on the line 2 2 oi Fig. l. Fig. 3 is a detail plan section of the valve-motor. Fig. 4t is an elevation of the shaft of this motor. Fig. 5 is a bottom plan view in detail of the cap of the valve-motor case. Fig. 6 is a detail plan section on the line 6 6 of Fig. l. Fig. 7 is an elevation of the inner face of the back head of the drill-cylinder removed. Fig. S is a rear end elevation of the drill-cylinder and the sliding frame carrying the same, the back end of the cylinder being' removed. Fig. 9 is a detail of the rotating bar and its ratchet- Wheel. Fig. lO is a vertical transverse section through the back head of the machine, some of the parts being shown in elevation. Fig. 1l is adetaillongitudinal section through the back head of the machine. Fig. 12 is a detail of the ratchet-spring. Fig. 13 is a side elevation of the pawl cooperating with the rotating ratchet. Fig. la is an elevation of the disk face ol? the same. Fig. l5 is an elevation of the disk face of the rotating ratchet. Fig. 16 is a side elevation of the same, and Figs. 17 and 18 are details of the pawl-oscil lating mechanism.

The main cylinder of the drill is shown at A, its reciprocating piston at B, its drill-oar (represented as being integral to the piston) at C, and its rotating bar at D. The rotah ing bar D is angular in cross-seetion and nts Serial No. 717,550. (No model.)

Within a suitable nut d, fitted Within the axial aperture, entering the pistou B from its rearward end.

The valve-chest is shown at E, and to this chest a pipe e leads pressure, usually compressed air. The controlling-valve Fy reciproeates within the chest E and is actuated by a rotary motor G, mounted upon the valvechest and having a crankshaft g, the cranl: of which is located Within the chest E and is connected with the valve F by means Oi a pitman H. Ports c c2 lead from the valvechest E to the opposite ends of the cylinder A, and exhaust-ports are shown at c3 el, one for each end of the cylinder and opening through the side Walls of the valve-chest, as shown in Fig. 6.

The valve F is a bar of sufficient length to overlap both pairs of the cylinder-ports and is provided at each end with a suitable cavity for connecting the cylinder and exhaust ports, the laps of the valve being such that the cylinder-ports c' c2 are alternately uncovered to the pressure Within the chest E. The rotary motor for actuating the valve F comprises a cylindrical head g', iixed upon the shaft g and located Within a suitable chamberiu the casing, the dimensions and form of this chamber being such that at diametrically opposite points the head g contacts with its Walls, the chamber being enlarged between and on both sides of these points of contact and havn ing curved Walls. Blades pf2-as shown, three in number-are iitted so as to reciprocate in radial recesses in the head g. A groove g3 in the bottom of the head g crosses the inner end of the recess Within which the blades g2 are located, and a port gl leads from the chamloer of the valve-chest E to this groove, thereby providing pressure for forcing the blades outwardly.

The ports g5 gf lead from the valve-chest through the Walls and top of the engine-case and open to its chamber. The head g'is provided in its upper disk face with segmental grooves g?, one between each pair of the blades g2, and ports g8 lead from these grooves to the periphery of the head. The grooves gl and ports g8 are so disposed that as ablade g2 passes one of the points of contact with the Walls of the cylinder-oase communication lOO stop-shoulder, as shown, and a port lo 7c leads from each end of the valve-chest E, so as to provide a constant pressure back of each of these cushioning-heads. The rotating-bar D passesV through the cushioning-head K, making a tight fit therewith, and into the back head of the cylinder, being journaled in both Walls thereof-that is to say, the wall M, which closes the end of the cylinder A, and the wall M. A ratchet-wheel O is fixed upon the bar D within the back head of the cylinder and is provided with a prolonged hub 0 and upon one of its disk faces and also upon its periphery with ratchet-teeth, as shown at 0 o2. An annular pawl P is mounted so as to oscillate upon the hub o and has ratchetteeth p upon its disk face which is adjacent to the ratchet o'. rlhe coil-spring Q, interposed between the outer disk face of the annular pawl P and the wall M of the back head of the cylinder, throws the teeth p of the pawl into engagement with the ratchetteeth o'.

Extending transversely across the top of the back head of the cylinder and opening to the chamber thereof there fis located a cylinder 22, within which therereciprocates a trunk-piston 21, having substantially midway of its length a transverse vertical aperture, within which there reciprocates a recessed shoe 23. An arm 24, extending radially from the pawl P, is provided with a head 25, which enters and is adapted to oscillate within the recess of the shoe 23, so that as the piston 21 reciprocates within its cylinder the pawl P is caused to oscillate, and when moving in one direction it necessarily carries the ratchetwheel O with it, and this turns the bar D, the piston B, and the drill-bar C. As the pawl P moves in the opposite direction its ratchetteeth p slip past the ratchet-teeth o. In order to prevent the retrograde movement of the ratchet-wheel O with the pawl, there are provided spring-pawls 26 27, housed in suitable radial pockets in the back head of the cylinder and engaging the peripheral ratchetteeth o2.

Movable cushioning-heads 28 29, similar to the heads K 7.o, are fitted within the ends of the cylinder 22, and ports 30 31 lead from the valve-chest E to the ends of the cylinder 22 back of such cushioning-heads, thereby providing an air-cushion for stopping the piston the piston 21 in one direction, and a port 33 leads from the port e' to the opposite end of the cylinder 22, so as to provide pressure for throwing the piston 21 in the opposite direction. When the valve F is in the position shown in Fig. 1, the port e' being in communication with the exhaust-port e3, the port 33 is of course also in communication with the exhaust-port, and at this time also the port 32 is uncovered by the valve F. When the valve Fis thrown in the opposite direction, it uncovers the port e3, thereby admitting pressure through the port 33, and it opens the port 32 to the exhaust-port e3.

By the above-described arrangement of parts it will be seen that the drill is given a partial turn each time it reciprocates. The pawl P being annular in form and, if desired, being provided, as shown, with as many teeth as the ratchet O, there is a distribution of pressure and consequent wear, which contributes materially to the durability of the parts.

The rotation being accomplished by iuidpressure and the same pressure being utilized to cushion the actuating-piston, the movement is not only certain, but is accomplished without violent impact of the parts one upon another.

We make no claim to the particular form of motor for actuating the valve F, nor do we claim as new the cushioning-heads for the cylinder A.

We claim as our invention-- 1. In a rock-drill, in combination a cylinder, a reciprocating piston therein, a rotating bar in sliding and non-rotating engagement with the piston, a ratchet-wheel fixed upon the rotating bar and having ratchet-teeth on its disk face, an annular pawl in parallel plane and concentric with the ratchet and having teeth on its disk face for engaging the teeth of the ratchet-wheel, such pawl being axially movable, means for yieldingly forcing the IOO IIO

lpawl toward the ratchet, and means for causing the oscillation of the pawl.

2. A drill-rotating device for rock-drills comprising an angular rotating bar, a wheel fixed thereupon Vand having ratchet-teeth on its disk face, an annular pawl having teeth on its disk face for engaging the ratchet-teeth, means for yieldin gl y holding the pawl against the ratchet, and means for oscillating the pawl.

3. In a drill-rotating device for rock-drills, in combination, an angular rotating bar, a ratchet-wheel fixed thereon, an annular pawl cooperating with the ratchet and having a radially-projecting arm, a cylinder transverse to the rotating bar, a piston 'reciprocating in the cylinder and having a transverse recess, and a shoe reciprocating within the recess, the arm of the pawl being in pivotal engagement with the shoe. Y

IZG

a radially-projecting arm, a cylinder transverse to the rotating bar, a piston reciprocating in the cylinder and having a transverse recess, and a shoe reciprocating Within the recess, the arm of the pawl being in pivotal engagement with the shoe.

5. In a drill-rotating device for rock-drills, in combination, an angular rotating bar, a ratchet-Wheel fixed thereon, a paWl for turning the iatchet-wheel, a piston for actuating such pawl, a cylinder within which the piston reciprocates,1novable cushioning-heads Within the cylinder,and means for delivering luidpressure back of such heads.

6. ln a uid-actuated rock-drill, in combination,a cylindena piston reciprocating therein and carrying a drill-bar, a valve-chest, ports leading from such chest to the opposite ends oit' the cylinder; an angular rotating bar on the axis oit' the cylinder and in sliding en gageinent with the piston, a ratchet-Wheel fixed upon the rotating bar and having teeth on its disk face, an annular pawl concentric with such bar and having annularly-arranged teeth for cooperating with the said teeth on the ratchet, a spring for forcing the pawl into engagement With the ratchet, an ar1n projecting radiall7 from the pawl, a piston for oscillating the paWl, such piston having a transverse recess and a shoe reciprocating therein, With which 'shoe the arm of the pawl is pivotally engaged; a cylinder Within which the last-named piston reciprocates, ports leading from the valve-chest to the opposite ends of the last-named cylinder, a valve for simultaneously controlling the ports of both cylinders, and a motor for shifting the valve.

7. In a drill-rotating device for rock-drills, in coinhination,a rotating bar,a ratchet-Wheel fixed thereon, and having teeth on its periphery and disk face, spring-retaining paWls co operating with the peripheral teeth, a springpaWl, annular in form, for engaging the disk-- face teeth of the ratchet-Wheel, and means for oscillating the pawlb GEORGE D. WHITGOMB. VILLIAM K. MILLHOLLAND.

lVitnesses to signature of George D. Vhit comb:

C. S. WHrrcoMB, JOHN E. DALY. Witnesses to signature of William K. Millholland:

LoU'is K. GILLsoN, E. M. KLA'rorrEB.. 

